Parallel motion picker stick mechanism for looms



g 1943- H. A. DAVIS msmm PARALLEL MOTION PICKER STICK MECHANISM FORLOOMS Filed Oct. 24, 1940 V s lnvenT 22 Hury A.DQ\/i Patenied Aug. 5,1941 ZZSMGI i" F i Q fl hAR-ALLEL MOTION PICKER STICK MEGHANISM FORLOOMS 6 Claims.

This invention relates to improvements in parallel motion picker stickmechanism for a loom and particularly to the bearing for the lower endof the picker stick against the pull of the lug strap or other mechanismby which the picker stick is moved or thrown to perform its function.

The picker stick is usually attached to a segmental shoe which rocksupon a flat rocker stand which is mounted uponthe lay rock shaft of theloom. The lower end of the picker stick is usually provided with atongue which projects through this stand and engages an abutment on therocker stand to hold the lower end of the picker stick against movementinwardly toward the loom side during the pull of the lug strap and theconsequent picking motion of the picker stick. This bearing is subjectto very trying conditions and if Worn or broken interferes with theaccurate operation of the loom or prevents the operation of the loom. Inusual looms the bearing or abutment is in the form of a wood plug or aniron plug anchored in the recess in the end wall of the rocker stand atthe inner end of the slot, or in some types of looms a fixed pin or aroller is mounted transversely of the inner end of the slot adapted tobe engaged by the tongue. Where abutment plugs are used the end of theplug becomes worn rapidly and uneven by the friction between it and thetongue of the picker stick, and where a pin or roller is employed thereis only a line of contact between the surface thereof and the pickerstick. In either case the abutment will wear out of line so that theshoe will become skewed with respect to the parallel shoe and the pickerstick will improperly engage the shuttle and in many inthe usual springactuated strap, which maintains thepicker stick tongue in connectionwith the abutment, will act as a hold-down to prevent separation of therocker from the rocker stand, notwithstanding the jerks upon the lugstrap and willinsure proper impingement upon the end of the shuttle andconsequent accuracy of the flight thereof.

Another object of the invention is to provide an oscillatory abutmentmember having a wide fiat convexedly curved face of considerable areaadapted to be engaged by the tongue of the concave end portion of thetongue of usual picker stick mechanism, and which can be mounted uponthe rocker stand by merely boring a trans verse hole through it andinserting a pin therein to provide a pivot for the abutment member sothat the present invention may be applied to usual types of loomswithout other modification than possibly the substitution of a tonguehaving a properly concave face to cooperate with that of the abutment inthe event that the concave face of the original tongue does not conformto the curvature of the oscillatory abutment.

If the rocker stand is provided with a tapered socket to receive theusual wooden or iron plug upon which the lower end of the picker stickis fulcrumed, the present invention 'may be readily applied thereto byinserting into the socket an iron plug having a horizontally positionedcylindrical end adapted to fit a complementary socket in an oscillatoryabutment member of the character described, thereby avoiding thenecessity of boring alined transverse holes in the rocker stand toreceive the pivotal pin for the oscillatory abutment member.

In usual constructions the tongue is clamped between the picker stickand the shank of the rocker shoe with an adjusting nut mounted in theupper end portion of the shank of the rocker bearing against the upperend portion of the tongue operable in conjunction with the clampingmeans to permit proper positioning of the icker stick. In suchconstructions the natural shrinkage of the picker stick loosens theparts to an appreciable extent, so that the set screw will wear a recesson the face of the tongue against which it has been jammed, requiringthe re-tightening of the set screw to secure a tight assembly and asthis wear continues eventually requires the replacement of the tongueonly to have the same trouble repeated.

A further object of the invention is to provide means for overcomingthis serious difficulty. This is accomplished in the present inventionby providing a hardened surface, preferably a chillhardened spot, on theface of the tongue near its upper end where it is engaged by the setscrew thereby preventing such wear andsaving of loss of time forrepeated adjustment and replacement of the tongue and consequent expenseof repairs and loss of production.

A preferred embodiment of the invention is illustrated in the drawing,in which,

Fig. l is a front elevation, partly broken away, of the lower right handportion of a loom embodying a preferred form of the invention andshowing the picker stick in its outward position;

Fig. 2 is a diagrammatic elevation showing the picker stick in avertical or intermediate position;

Fig. 3 is a similar diagrammatic view showing the picker stick in aninner position;

The different positions of the picker stick illustrated in Figs. 1, 2,and 3, show the manner in which the engagement of the complementarycurved bearing surfaces of the tongue and abutment, in combination withthe spring actuated strap for returning the picker stick to outerposition, acts as a hold-down for the picker stick assembly;

Fig. 4 is a sectional view on line 4l iv Fig. 1 viewed from the lefttoward the right, illustrating particularly the chilled spot on thetongue which is engaged by an adjusted screw; and,

Fig. is a detail view, partly in section, of a modified embodiment ofthe invention.

As the picker stick motion andits purposes and function in the operationof the loom are well known and; familiar to those skilled in the art, itis only necessary to illustrate and describe the same so far as isnecessary to the disclosure of the present invention.

In the construction illustrated the right side I of the loom frame isshown as supporting the usual rocker stand 2 for the picker stick shoe.The rocker stand is mounted as usual upon the lay rock shaft andprojects laterally from the loom side and is provided with a flat uppersurface 3 on which the shoe of the picker stick mechanism rocks. Therocker stand is provided adjacent its outer end with a. longitudinalslot 4 through which the lower end of the picker stick extends. It isalso provided with an upwardly extending tongue 5 which extends into aslot in the shoe and forms a guide for the rocking shoe or rocker. Therocker 6 may be and is of a usual construction having an arcuate sole 1which rests and rocks upon the flat surface 3 of the rocker stand. Therocker is provided with an upwardly extending channel-shaped shank 8 andthe picker stick 9 extends downwardly through the channel and through aslot in the shoe and also through the slot 4 in the rocker stand.

A channel-shaped tongue In, which fits upon the picker stick and betweenthe walls of the channel-shaped shank of the rocker shoe, is clampedbetween the picker stick and the base of the channel of the rocker shoeby a bolt l I which passes through the tongue and picker stick andthrough a U-shaped clamping member l2, the flanges of which embrace thesides of the, picker stick, a nut I?v upon the bolt H serving when setuprigidly to secure the. parts together.

In order to provide for proper adjustment of the picker stick relativelyto the shoe, an adjusting screw [4 is mounted in the upper portion ofthe shank 8 and is provided with a lock nut IE to, secure it in adjustedpositions. In usual constructions this adjusting screw engages the faceof the upper portion of the metal tongue which is of relatively softermaterial than that of the screw. By reason of the shrinking of the stickand the intense vibration of the picker stick as it is actuated by thelug strap mechanism the set screw rapidly wears a recess into the faceof the tongue in usual constructions. One of the objects of the presentinvention is to prevent such wear. This is accomplished by providing ahardened and chilled spot I6 in the portion of the upper face of thetongue which is engaged by the set screw and it is found that thisimprovement, though apparently simple, substantially obviates thenecessity of repeated adjustments of the set screw and clampingmechanism to maintain the picker stick in proper operating position.

The principal object of the invention as above stated is to provide anovel bearing mechanism between the tongue and an oscillatory stop orabutment which will provide extended cooperating bearing surfaces whichwill minimize wear and practically eliminate misalinement of the pickerstick mechanism relatively to the shuttle and to the lay which istraversed by the shuttle, thus insuring accurate flight of the shuttleand preventing injury to the picker stick, the shuttle or to the guidesand lay parts, thereby avoiding the expense of overhauling in order tosecure a safe running shuttle.

This is accomplished in the embodiment of the invention illustrated inFigs. 1, 2, and 3, by providing an oscillatory stop or abutmentcomprising a preferably metal block I! of generally triangular shapewhich is pivotally supported upon a stud I8 which extends transverselyacross the slot 4 of the rocker stand and is mounted in suitable alinedholes in the walls of the slot. Desirably a hardened and anchoredbushing I9 is mounted on the stud l8 to provide a suitable journal forthe oscillatory abutment. The outer face of the abutment block I! isprovided with a wide transversely flat longitudinally convex face 20 andthe lower end portion of the tongue H] has a wide transversely flatlongitudinally concave face 2| which is complementary to the face 20 ofthe abutment block.

By reason of this construction extended contacting bearing surfaces areprovided on the abutment and on the tongue which will avoid skewing ofthe rocker shoe and insure proper alinement of the picker stickmechanism with the lay at all times so that the accuracy of the flightof the shuttle will always be maintained.

The mechanism for pivotally swinging the picker stick to its outermostposition is illustrated in Fig. 3 and may be and preferably is a usualstrap 22 which is connected at one end to a hook 23 upon the end of thespring of a spring drum 24 which is mounted upon brackets 25 secured toand extending downwardly from the rocker stand. The other end of thestrap 22 extends beneath the curved lower end 26 of the picker stick andis clamped to the picker stick between the U-shaped clamping member 12and the outer face of the picker stick.

In usual constructions there is in the course of the sweep of the pickerstick a time when the spring actuated strap between the lower end of thepicker stick and the spring drum becomes practically horizontal and thehold-down effect of the spring and strap becomes ineffective and sinceat about this time the contacting surface of the spring with the plugabutment or roll assumes nearly a vertical position the pull of the lugstrap between the pick arm and the picker stick will cause the shoeassembly to be raised or separated from the horizontal or parallel faceof the rocker stand, thus causing improper engagement of the pickerstick with the shuttle and causing the shuttle to wear badly at the topand at the same time to be distorted from a true parallel flight withrespect to the lay. This will result often in bang-offs, brokenshuttles, and spoiled cloth.

One of the objects of the present invention is to overcome theseinherent troubles of older constructions and insure accurate flight ofthe shutv tle parallel to the lay which is so important to a goodrunning shuttle.

This is accomplished in the present invention by so constructing,positioning and arranging the oscillatory abutment and the tongue thatthe lower end of the tongue extends at all times across a vertical planethrough the axis of the stud l8 so that the constant pull upon the strap22 in cooperation with the complementary curved surfaces 20 and 2| ofthe oscillatory abutment and the tongue will exert a vertical resultantforce in the vertical plane of the axis of the stud l8 which willprevent separation of the rocker shoe from the parallel face of therocker stand, while permitting such constant contacting and slidingrelation of th contacting surfaces 20 and 2| during the entire rollingor rocking motion of the shoe assembly on the rocker stand throughoutthe complete sweep of the picker stick at each pick.

This hold-down action is illustrated in Figs. 1, 2, and 3, which showthe relation of the parts in Fig. 1 when the picker stick is swung toits outermost position, in Fig. 2 when the picker stick is substantiallyvertical, and in Fig. 3 in which the picker stick is swung to itsinnermost position.

By reason of th present construction therefore the contacting surfacesof the tongue of the picker stick and the oscillatory abutment maintaina constant relation over an extended area which eliminates wear andbecause of the established relation of the curved contacting surfaces ofthe tongue and oscillatory abutment the under convex surface of thtongue against the convex surface of the abutment produces a constanthold-down effect for the entire rocker assembly throughout the entirepick and sweep of the picker stick.

One of the objects of the invention as above stated is to provide anoscillatory abutment of the character specified which can be readilyapplied to picker stick mechanisms of usual loom types of constructionssuch as those having an abutment in the form of a plug or an abutmentroller which is engaged by the tongue of the pickor stick. In such usualloom constructions the lower end portion of the picker stick is usuallyconcavedly curved and in the event that such curvature presents a properarcuate surface an oscillatory abutment of the character above describedhaving a convex face complementary to the curvature of that of thepicker stick may be mounted upon a suitable stud which may be readilyapplied to the usual rocker stand by boring axially alined holes throughthe wall of the slot in the rocker stand at a proper distance from theinner end of the slot. In the event that the curvature of the lower endof the usual picker stick tongue of an old machine is too great or toosmall the present invention may be applied by merely substituting a newtongue having a curvature complementary to the curvature of the face ofthe abutment which may be mounted in the manner above described.

Where the rocker stand 3 of the loom, to which the invention is to beapplied, is provided with a tapered socket 21 to receive a wooden oriron plug upon the end of which the picker stick is to be fulcrumed, thepresent invention may be readily embodied in such construction byinserting into said socket a steel plug having a tapered end portion 28complementary to and fitting said socket with a reduced neck portion 29integral with a cylindrical head 30 extending transversely of the slot 4in the rocker stand. In this construction the oscillatory abutmentmember 3| is provided with a cylindrical socket 32 complementary to andextending more than half Way around the cylindrical head 30, therebyforming a pivotal connection for the oscillatory abutment member whichwill not become detached during its operation. The oscillatory member isprovided with a curved face 33 complementary to the curvature ill of thelower end of the picker stick tongue. The operation of thisembodiment ofthe invention is the same as that above described in respect to Figs. 1,2, and 3.

It will be understood that the particular embodiment of the inventionshown and described herein is of an illustrative character and is notrestrictive and that various modifications in form, construction ormaterials may be made within the spirit and scope of the followingclaims.

Having thus described the invention, what is claimed as new, and desiredto be secured by Letters Patent, is:

1. In a parallel motion picker stick mechanism for a loom having arocker stand provided with a longitudinal slot, a rocker mounted on saidstand and a picker stick having a metal tongue secured to said rockerand extending through the slot in said rocker stand, a bearing. for saidpicker stick comprising an oscillatory abutment member pivotally mountedon said stand within said slot having a long longitudinally convexedlycurved bearing surface and a complementary long ccncavedly curvedbearing surface on the tongue of said picker stick contacting therewithsubstantially throughout its length and means for maintaining continuousengagement of said complementary surfaces during the actuation of thepicker stick, whereby proper alinement of the picker stick mechanismwill be maintained.

2. In a parallel motion picker stick mechanism for a loom having arocker stand provided with a longitudinal slot, a rocked mounted on saidstand and a picker stick having a metal tongue secured to said rockerand extending through the slot in said rocker stand, a bearing for saidpicker stick comprising an oscillatory metallic abutment memberpivotally mounted on said stand within said slot having a longtransversely fiat convexedly curved surface and a complementarytransversely fiat concavedly curved surface on said tongue complementarythereto, and means for maintaining continuous engagement of saidcomplementary surfaces during the actuation of the picker stick.

3. A parallel motion picker stick mechanism for a loom comprising arocker stand provided with a longitudinal slot, an abutment memberpivotally mounted on said stand within said slot having a widetransversely flat longitudinally curved convex surface, a rocker mountedon said shoe, a picker stick mounted on said rocker extending throughthe slot in the rocker stand and provided with a tongue having atransversely wide concave surface complementary to the surface of saidabutment member and extending beneath the pivotal axis of said abutmentmemher, and resilient means for maintaining continuous engagement ofsaid complementary surfaces during the actuation of the picker stickacting in conjunction with the engaged complementary surfaces as ahold-down to prevent separation of the shoe from the rocker stand andthus insure proper flight of the shuttle.

4. A parallel motion picker stick mechanism for a loom comprising arocker stand provided with a longitudinal slot, a rocker mounted on saidstand and a picker stick provided with a metal tongue having a widetransversely fiat concave end portion secured to said rocker andextending through the slot in said rocker stand, a stud mounted in thewalls of said stand extending transversely across said slot, a metalbushing mounted on said rod and a metal abutment block having anaperture through the upper portion thereof fitting and rotatably mountedon said bushing and provided with a transversely wide longitudinalconvex face complementary to the concave face of the tongue.

5. A parallel motion picker stick mechanism for a loom comprising arocker stand provided with a longitudinal slot and having anabutment-receiving recess in the inner end wall of said slot, a rockermounted on said stand and a picker stick provided with a metal tonguehaving a wide transversely flat concave end portion secured to saidrocker and extending through the slot in said rocker stand, an abutmentmember seated in said socket having a cylindrical head, and a metalabutment block having a transverse aperture therethrough complementaryto and rotatably mounted upon the cylindrical head of said abutment andprovided with a transversely wide longitudinally convex facecomplementary to the concave face of said tongue.

6. An oscillatory abutment-block for a parallel motion picker stickmechanism for a loom having a rocker stand provided with a longitudinalslot, a rocker mounted on said stand and a picker stick provided with ametal tongue having a Wide transversely flat concave end portion securedto said rocker and extending through the slot in said rocker stand,comprising a metal block having a transversely wide longitudinal convexface complementary to the concave face of said tongue and adapted to bepivotally mounted upon a stud extending transversely across the innerend of the slot in the rocker stand.

HARRY A. DAVIS.

